Try to focus on getting one fish to breed. If you have all those fish in one tank, it is most likely that the other fish will just eat all the eggs. First you have to look at; do you have enough room for 100 fry if they do spawn? Secondly, once you've selected on what one fish you want to breed, find out the requirements to breed them (cold water changes, pH, temperature, feeding ect). My idea is to put them in one species tank to try and get them to breed.
HTH